R. N. Salaman 1S3 



used, but it was sown with tlie following artiiiciai.s : superphospliate 

 84 lbs., sulphate of ammonia 2(1 lbs., and kainit 28 lbs. The guard rows 

 were treated in like manner. 



Eleven classes of seed tubers were selected, boxed and sprouted, on 

 the same date. In each class the seed was weighed, pound by pound, so 

 that there was a check both as to size and individual weight. Thus, 

 ehminating as far as possible, any source of error arising from ine(iuahty 

 of seed within each class, an error which has vitiated some otherwise 

 valuable work in past years. 



Class A. Tubers weishing 0-6 oz. or 2l> to 1 lb. 



B. ., „ 1-33 ozs. „ 12 



C. „ ., I'-O „ „ 8 

 D- „ ,. -'-66 „ „ 6 



E. „ „ 4-0 „ „ 4 



F. ,. ,. .5-33 „ „ 3 

 U. Mixed unselecteil seed tubers. 



H. VVlicile tiiljers with outgrowtlis weigliiiig 2 ozs. eaeli. 



I. Tlie erown ends from tubers with lateral outgrowths 



w^eighiiig 1-66 ozs. each. 

 J. Cut sets with outgrowths weighing 2 ozs. each. 

 K. Qut sets with outgrowths, weighing 1'2.5 ozs. each. 



All tuber-sets presented short, strcuig sprouts and no blind sets were 

 planted. 



Of these classes, B, C, D and G were present in sufficient quantity 

 to plant five rows of 100 tubers each. A and E filled three rows respec- 

 tively of 100 tubers each. F was sufficient for one full row and part of 

 another. H, J and K were present only in sufficient quantities to plant 

 part rows of each. It should be noted that in a standard plot, viz. a row 

 100 feet long, not only was the number of sets the same, but in respect 

 to any class, the total weight of sets was e.xactlv the same. 



Th.e experiment was planned on the checker-board system (see Fig. 1 ), 

 but in place of square plots, single rows were used. As the variety was 

 the same throughout, no need was felt for guard rows of some neutral 

 variety between the rows, but surrounding the whole experiment were 

 rows of the variety Golden Wonder, each section containing 100 tubers. 

 On the northern side two rows of Golden Wonder were succeeded by a 

 crop of barley, on the south the two rows were followed by more potatoes. 



The rows were exactly two and a half feet apart and the tubers were 

 sown by hand, the distance between the centres of every two consecutive 

 tubers being one foot. The spacing between tubers was carefully con- 

 trolled by actual measurement as each tuber was planted. The covering 

 in, first hoeing, and earthing up were done by horse labour. 



Joum. of Agric. Sci, xn. 13 



